content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2013 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf.nano;
  
  import java.io.IOException;
  
  /**
   * This class is used internally by the Protocol Buffer library and generated
   * message implementations.  It is public only because those generated messages
   * do not reside in the {@code protobuf} package.  Others should not use this
   * class directly.
   *
   * This class contains constants and helper functions useful for dealing with
   * the Protocol Buffer wire format.
   *
   * @author kenton@google.com Kenton Varda
   */
  public final class WireFormatNano {
    // Do not allow instantiation.
    private WireFormatNano() {}
  
    static final int WIRETYPE_VARINT           = 0;
    static final int WIRETYPE_FIXED64          = 1;
    static final int WIRETYPE_LENGTH_DELIMITED = 2;
    static final int WIRETYPE_START_GROUP      = 3;
    static final int WIRETYPE_END_GROUP        = 4;
    static final int WIRETYPE_FIXED32          = 5;
  
    static final int TAG_TYPE_BITS = 3;
    static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
  
    /** Given a tag value, determines the wire type (the lower 3 bits). */
    static int getTagWireType(final int tag) {
      return tag & TAG_TYPE_MASK;
    }
  
    /** Given a tag value, determines the field number (the upper 29 bits). */
    public static int getTagFieldNumber(final int tag) {
      return tag >>> TAG_TYPE_BITS;
    }
  
    /** Makes a tag value given a field number and wire type. */
    static int makeTag(final int fieldNumber, final int wireType) {
      return (fieldNumber << TAG_TYPE_BITS) | wireType;
    }
  
    public static final int EMPTY_INT_ARRAY[] = {};
    public static final long EMPTY_LONG_ARRAY[] = {};
    public static final float EMPTY_FLOAT_ARRAY[] = {};
    public static final double EMPTY_DOUBLE_ARRAY[] = {};
    public static final boolean EMPTY_BOOLEAN_ARRAY[] = {};
    public static final String EMPTY_STRING_ARRAY[] = {};
    public static final byte[] EMPTY_BYTES_ARRAY[] = {};
    public static final byte[] EMPTY_BYTES = {};
  
    /**
     * Parses an unknown field. This implementation skips the field.
     *
     * <p>Generated messages will call this for unknown fields if the store_unknown_fields
     * option is off.
     *
     * @return {@literal true} unless the tag is an end-group tag.
     */
    public static boolean parseUnknownField(
        final CodedInputByteBufferNano input,
        final int tag) throws IOException {
      return input.skipField(tag);
    }
  
    /**
     * Computes the array length of a repeated field. We assume that in the common case repeated
     * fields are contiguously serialized but we still correctly handle interspersed values of a
     * repeated field (but with extra allocations).
     *
     * Rewinds to current input position before returning.
     *
     * @param input stream input, pointing to the byte after the first tag
     * @param tag repeated field tag just read
     * @return length of array
     * @throws IOException
     */
    public static final int getRepeatedFieldArrayLength(
        final CodedInputByteBufferNano input,
        final int tag) throws IOException {
      int arrayLength = 1;
      int startPos = input.getPosition();
      input.skipField(tag);
      while (input.readTag() == tag) {
        input.skipField(tag);
        arrayLength++;
      }
      input.rewindToPosition(startPos);
      return arrayLength;
    }
  
  }
  